The present invention relates to signal assemblies and particularly to signal assemblies which utilize flashlamps. Even more particularly the invention relates to flashlamp signal assemblies which are capable of being used in alarm systems.
It is known in the art to utilize flashlamp signal devices as part of an alarm system. Attention is called to U.S. Pat. Nos. 3,714,647 (A. L. Litman) and 3,805,257 (A. L. Litman et. al.) wherein signal devices are described which incorporate multiple flashlamp elements. The preferred elements for use in these devices are sold under the name "MAGICUBE" and are produced by the assignee of the present invention. Triggering the percussive flashlamps in the above devices is accomplished via a spring-loaded pivotal arm which moves in response to some external activation, e.g. pulling of an attached cord or chain.
In addition to providing a highly intense flash, e.g. 2000 beam candle power seconds, the devices are operatively connected to an electrical circuit which includes therein a photovoltaic cell or similar component which becomes activated upon receipt of the light flash from the fired lamps within the device. As a result, an audible alarm is produced.
A major disadvantage of devices like those above is the requirement for using electrically-operated audible signal generating components. If such a device is incorporated within an alarm system which in turn is electrically connected to normal line current (as in home or industry), the audible portion of the system is inoperative during periods of electrical failure, e.g. "blackouts". If batteries are used instead, the audible portion of the system is operative only when the voltage level of these components is sufficient. It is further necessary to periodically replace these components, which adds appreciably to the overall cost of the system. With devices using electrical circuitry and components, there are also the problems and disadvantages of faulty connections, electrical shock, etc.
Still another problem with alarm systems employing electronic light-activated components spaced from the light source involves the possibility of interruption of the activating light by a window shade, drape, etc. Such interruption of course prohibits subsequent emission of the necessary audible warning.
It is believed therefore that a flashlamp signal device which is capable of emitting both highly intense audible and visual signals in alarm situations and which operates without the need for electrical components and circuitry would constitute an advancement in the art.